AI4Car quick readA short, original guide from the AI4Car knowledge library.
Write down whether the engine is cold or warm, whether the A/C is on, and whether the symptom appears in Park, Neutral, or Drive. Those details help make a repeatable check.
A warm-only rough idle can have several causes. If you have scan data, compare idle speed, fuel trims, and misfire counts; a pattern across cylinders can be more useful than replacing parts one by one.
Quick educational note
For information, not a diagnosis or repair instruction. Vehicle-specific checks are still required. Consult the manufacturer's guidance and a qualified technician.
How to use this information
This article explains general principles and does not establish what is wrong with your vehicle. Read the content limitations.